There are a couple of threads regarding the different polish blanks out there. We came up with at least 3 different versions being sold right now. The one with the sanded surface was deemed least desirable. They are apparently made from a different grade of steel than the others and there have been some heat treating issues with them.
Stick with the ones from AK-builder or Copes.

“The very atmosphere of firearms anywhere and everywhere restrains evil interference- they deserve a place of honor with all that is good.”George Washington

"A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." George Washington